$(a)$ What is an electromagnet? What does it consist of?
$(b)$ Name one material in each case which is used to make a: $(i)$ permanent magnet $(ii)$ temporary magnet.
$(c)$ Describe an activity to show how you can make an electromagnet in your school laboratory.

(N/A) An electromagnet is a device that produces a magnetic field around its conductor coil when an electric current is passed through it. It consists of a core of soft iron or its alloy and a solenoid conductor coil wound around the core.
$(b)$ $(i)$ Alnico alloy is used for making permanent magnets.
$(ii)$ Soft iron is used for making temporary magnets.
$(c)$ Take about $10$ iron nails of equal length and wrap an insulated copper wire around them in the form of a solenoid coil. Now,connect this arrangement to a battery and a key switch as shown in the diagram. When the current is passed through the coil,the nails inside the coil act as a core and become magnetized. Such an arrangement is called an electromagnet.